1. Field of the Invention
The present disclosure relates to airfoils, and more particularly to cooled airfoils for blades and vanes in gas turbine engines.
2. Description of Related Art
Blades and vanes used in turbine sections of modern gas turbine engines can require active cooling in order to operate at gaspath temperatures in excess of the melting temperatures of the blades and vanes. One solution for providing the necessary cooling is to supply pressurized cooling air to a cavity within each blade or vane needing cooling, and to distribute the cooling air through cooling holes that pass from the cavity out to the gaspath.
In such applications, it is generally desirable to control the direction of the cooling flow over the surface of the blade or vane. The ratio of a cooling hole's length to its diameter, the L/D ratio, is a determining factor in how much control designers can expect to have over the cooling air flow. As trends for higher performance engines drive a need for thinner blade and vane walls, there is a tradeoff between losing control of cooling flow due to reduced L/D ratio for cooling holes, and the benefits of thinner blade and vane walls.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for improved airfoils, e.g., for blades and vanes in gas turbine engines. The present disclosure provides a solution for this need.